Variable-tension expression-bellows for pneumatic apparatus.



No. 896,686. PATENTED AUG. 18, 1908.

G. P. BRAND.

VARIABLE TENSION EXPRESSION BELLOWS FORPNEUMATIO APPARATUS.

APPLICATION FILEDVJUNE 29, 1907. BB'NEWBN ULY 1B, 1908.

2 SHEETS-SHEBT 1.

No. 896,686. PATENTED AUG. 18, 1908.

' G. P. BRAND.

VARIABLE TENSION EXPRESSION BELLOWS EA'OR PNEUMATIC APPARATUS. APPLICATION FILED JUNE 29, 1907. RENEWED JULY J 908.

2 SHEETSSHEET 2.

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. Y 4/ f fiww GEORGE P. BRAND, OF NEW YORK, N. Y.

VARIABLE-TENSION EXPRESSION-EELLOWS FQR Pl TEUIEATIG AEEARATUB.

Specification of Letters Patent:

r cemes Aug. is, ices Application filed. June 29, 1907, Serial No. 3BL418. Renewed July 18, 1908. Serial Flo. 4424,2013.

To all whom it may concern:

Be it known that l, GEORGE P. BRAND, a citizen of thc United States, residing in the borough of the Bronx, city, county, and State of New York, have invented certain new and useful improvements in Variable- Tension Expression-Bellows for Pneumatic Apparatus, of which the following is a specification.

My invention relates to variable tension expression bellows lor pneumatic apparatus used in automatic music playing devices, to control connnunication between the exhaust mechanism 'and the wind chest with which the sound? actuating pneumatics are connected, and designated as the expression bellows, i

The objectol the invention is to automatically relieve the tension in the expression bellows by the admission of air thereto whenever the bellows is thrown into commufnication with a condition of high tension infrom a relatively high tension to afford a lower tcnsion,-the admission of air neutralizcs or counterbalances, the external )rcssure upon the movable member of the bellows. By this means the tendency to kick or collapse suddenly and forcibly when thctension is suddenly increased in the expression bellows is overcome or checked in its incipient stage, and provision is made [or changing or setting the throttling mechanism to a desired decrease or normal tension without having to wait until the high tension is relieved by air from the wind chest and this result is accomplished irres ective "of the position of the throttling mec anism within the bellows. That is to say the relief valve will be iini'nediately available and operative at both extremes of adjustment of the throttle mechanism or at any intermediate position thereof, as hereinafter more fully set forth.

' The invention consists essentially in. ro-

viding the variable tension bellows wit a rcliei valve which is opened by the movable member of the bellows whenever said movable-member is sulliciently collapsed forthe purpose or whenever the throttle mechanism is set to a lower tension, and in certain other features licrcim ltcr described and claimed specifically v tension bellows.

In the accompanying drawings, Figure 1, 55.;

shows diagrammatically an arrangement of parts whereby my variable tension bellows I may be cut ofi temporarily from communication with the wind chest and the latter thrown into direct communication with the main storage or exhaust mechanism; Fl 2, is a sectional detail of my improved. bellows showing an alternative construction; Fi 3,

- is a sectional view showing the port bloc in a different position from that shown in Figs; 1 and 2:E1g. 4, is a sectional view upon an enlarged scale showing the relative positionsof the parts just rior to the opening of the relief valve; and i ig. 5, a similar view Show-' ing the relief valve open.

n illustrating the practical application of; my invention 1 herein show and describe my improved variable tension bellows as used in conjunction with means for throwing the wind chest into direct communication with the main storage of the exhaust when unusually quick, full and powerful accentuation is required, although this arrangement forms no ,part of my presentinvention nor do I limit myself to such use of my variable Furthermore the latter is shown as provided with a movable ort block as in my concurrent applications os. 281,835 filed October 7, 1905, and 296,311

filed January 16, 1906, although I do not restrict myself in this res set.

In the drawings represents a wind chest of any desired construction with which the sound actuating neumatics are connected,said wind chest being also in com munication, indirectly, with the variable tension bellows A, and with the exhaust mechanism B. Thus, the variable tension bellows A is shown as connected with the main storage bellows M, interposed between it and the exhaust mechanism B, andwith the valve chest L, interposed between it and the wind chestW, said valve chest L, being also in communication with the main store;

age bellows M.

The variable tension bellows A, consists essentially of a stationary member A, and a movable member M, the parts being united in the usual manner by flexible material a. A long sensitiue spring S is interposed be tween the members A, A and tends constantly to separate them, even against internal tension.

Attached to the stationary member of the bellows A, is a pneumatic B", communieating, through the exhaust d net 71, with the main storage bellows ill. J ittachcd to this internal. pneumatic B, is an :uljustable port block R the interior passage I) being in eon'imunication with the interior of the pneumatic B, as will be seen by reference to iiig. 4. The sides of the iort block B, are formed with ports p, p, and its position in the variable tension bellows It is regulated and controlled manually or otherw'sc by means of a rod (Z, pivotally connected to the port block B and extending through a packed guide I), in the stationary member of the bellows. Pivotally secured to the op- )osed sides of the port block B are valve blades V, V, which are also,pivotally eonnected to the movable member A, of the bellows by means of the linhs e, '0. The sides of the valve blades V, V, opposed to the port block B are faced with leather or other packing to insure a close l'ricti mal contact therewith. The adjustable port block B", being set to represent a prescribed degree of tension in the wind chest W, any air admitted to the latter through the note sound-- ing neumatics will inflate the bellows A, more or less and thereby cause the valve blades V, to increase the available area of the ports p, proportionately, which will allow the tension reservoir M, and exhaust mechanism B to quickly withdraw such excess of air. As the prescribed normal tension is thus restored to the wind chest Vi the increase of tension in the bellows A, causes its movable member A, to collapse more or less and partially close the ports 1), according to dill'crenccs in. tension existing in the tension reservoir M, or exhaust mechanism B, as compared with that in the wind chestit" 'lhus the tension in the main storage reservoir M, or exhaust mechanism B, being gneatcr than in the wind chest, the movable member A of the variable tension bellows A, will move towards the stationary member A, sulliciently to cause the valve blades V, V, to close the ports p, until air admitted to the wind chest as before stated again re duccs the degree ol' tension therein and allows the movable member A ol the bellows A to move away from. the stationary member A, under the action of the spring S, and these pulsations will be repeated continually and autonnitically during the ())t)[tttl(lll ol' the ap aratus, the number and extent of the fluctuations being dependent upon the requirements of the music executed.

Provision is thus made tor-ordinary aeeentuation by means of the pneumatic A, and also for extraordinary or very powerful accentuation when desired b means which admit of the wind chest being thrown temporarily into direct communication with the main storage reservoir M. This I accomplish by connecting the wind chest W, with the middle chamber l, of the valve chest L, having end chambers l, and Z, connected re spectively by means of the duct m, with the main storage reservoir M, and by means of a duct o, with the variable tension bellows A. The partitions Z and Z, which divide the chest ii, into the three eonipartments Z, Z, Z, are each formed with ports and valve seats opening into the central com nn'tment Z. These ports are closed alternately by valves in and 121?, upon a rod N, the opposite ends of which abut against diaphra 'ms Z, t'. The space back ol the dia mra Z, communicates with the atmosphere through a hole 1, in the end of the chest L, and the space back oi. the other diaphragm t", comn'innicates through a duet Z, with a middle chamber 9' in a. secondary valve chest .l: which is formed with an air chamber r, connecting with the atmosphere and with a tension ehan'iber 7", communicating through the duct 1"", with the tension chamber 5, in the valve chest L. in the lower part of the chamber r", is 21 dia phragm r", upon which rests the lower end. of a valve stem 3, said stem carrying two valves 5, and 5', arranged respectively to engage al tcrnatcly with seats .in the partition which separates the middle chamber 7' from the other. The space under the diaphragm r, comnumicates through the duct t with a valve seat 6, U')0I1 which. the valve 4) is held normally by the spring w, interposed between a stationary part and the finger button on the other end of the valve stem v In Fig. 1, the parts are shown as in their normal position in relation to each other, in which condition the wind chest 'W is in communication with the variable tension bellows A.

When accentuation is desired by direct connnunication with the main tension reservoir M, the variable tension bellows A, is cut oil' and. the wind chest N, thrown into direct co]nmunieation with said main storage-bellows M. This is done by depressing" the button '1), which admits air-under the diaphra gni 1", thereby raising the spindle s, and admitting air to the dia} hragm Z"',' in the chest l1, resulting in the opening of the valve m, and the closing of the valve m which let tcr shuts ell? communication between the chest L and the interior of the bellows, at the same time putting the wind chest W in com.- munieation with the tension reservoir M through the medium oi. the chamber Z, and conduit mi As a result of this cutting off of the air l'roln the wind chest and the conse,

( uent imrrclase o l tension within the bello 'tlie movablb member M, will cause the hind V to close the ports 1), in. the portlilocli ii, without however disturbing the :uljustnmnt ot' thela't'ter. When comnumieation is recstablished between the variable tension chamher A and the wind enest "d", by the release and closing of the valve 4), and the constion with the high tension reservoir M, causes the movable member A, of the bellows to suddenly collapse still further,the inner side of said movable member A coming in violent contact with the buffer 1), on the port block B under ordinary conditions as heretofore existing thereby forcing the rod (1, back and disturbing the relative adjustment of the parts to which they have been set to afford a prescribed normal tension when the air from the wind chest VV' is passing through the bellows A, as hereinbefore mentioned.

The distinguishing feature of my present invention consists in obviating this kick or disturbance of parts created by the sudden increase of tension within, the bellows A,

when communication is reestablished with the wind chest, by means of a relief valve a,

mounted upon the movable member A and actuated automatically by an internal valve opener b, when the movable member A is sufficiently collapsed. The opener I), also acts to open the relief valve when the throttle mechanism is set to a lower tension, as when the movable port block is moved outward toward the movable member A The degree of projection of the valve opener b, is such that the valve will in either case be opened just prior to the contact of the movable mem ber A withthe buffer 5 so as to admit air to the interior of the bellows A, before actual contact and thereby prevent the jar and con cussion that would otherwise result.

The valve opener I), is shown as pro ecting from the buffer 1)", although this is not essential provided said buffer b, is pr'operly placed and timed with relation to the relief valve a. An external spring a, may be used in connection with the relief valve a, to hold it in its normal position if desired although this is not absolutely essential sincethe ten sion within the bellows will ordinarily hold it closed under normal conditions of use. The air thus admitted through the relief valve to counterbalance the external weight of the -at mosphere on the movable'inember A en-' ables the spring S to react against the movable member pushing it away from the' valve opener I), and allowing the latter to close, so thatthe prescribed normal tension will be restored, since the adjusting rod d,-*has remained undisturbed by the collapse of the movable member A. Thus the relief va ve is an important factor in the practical operation ofa variable tension bellows of the character designated, since it obviates all jaror I disturbance of the parts and renders the resetting of a prescribed normal tension unnecessary; or if a change of setting to afford a lower tension is desired, it enables such this connection it is to be noted that the re-' I lief valve is always available and ready no matter what the adjustment of the port block may be since the movable member A and blades V adapt themselves automatically in position with relation to the port block B.-

By mounting the adjustable port block B upon the pneumatic B, as herein shown:

and described, in lieu of on the hollow trunnion as in my concurrent application hereinbefore recited, I reduce frictional contact and obviate all danger of corrosion of parts, nce. the use of metal for this purpose is thereby a oided; I

It is. t be notcd that there is practically little or no loss of energy involved in the use of my relief valve, since only enough air is admitted thereby to the bellows to restore the normal tension to which the partsare set.

What I claim as my invention and desire to secure by Letters Patent is,

1. In a variable tension bellows of the character designated, the combination with the throttle mechanism, of a relief valve actuated thereby, for the purpose described.

2. In a variable tension bellows of the character designated, the combination with the port block and port-controller, of arelief i i valve and means upon the port block for op-- erating said relief valve, for the purpose dc scribed.

3. In a variable tension bellows of'the character designated, the combination of an adjustable port block, a port controller, a re- 7 lief valve on the movable member of the bellows, and means upon said adjustable port block for opening said relief valve, for the purpose described.

4. In variable tension bellows of the character designated, the combination with; ad-

justable internal throttling mechanism of a relief valve on the bellows and means controlled by said throttling mechanism where by said relief valve is rendered o erative thereby in the various'positions to which the throttling mechanism may be adjusted, for the purpose described.

5. In variable tension bellows of the character designated, the combination of internal throttling mechanism interposed between high tension and low tension, means foradjusting said throttling mechanism, a,rclief e valve, and means upon'said throttling mech anism for operating said relief valve, for the purpose described.

6. In a variable tension bellows of the character designated, the combination of internal throttling mechanism interposed between the high tension and the low tension,

means for adjusting said throttling mechanism, a relief valve and means upon said. throttling mechanism. for operating said relie'l' valve during the change from a high to a lower tension, for the purpose set forth.

7. In a. variable tension bellows of the character designated, the combination of in lit ternal. throttling mechanism interposed be tween the high tension and the low tension, means l'or ad justing said throttling mechanism 'lor operating said relief valve during the collapse oil the movable member of the bellows for the purpose described.

8. in a variable tension expression bellows oi the character designated, the combination ol' a port block mounted ad justably upon one member of the bellows, means ior connecting said adjustable port block With a tension reservoir or exhaust mechanism, a valve blade connected with the other member of the bellows, means for adjusting said port block with relation to said valve blade, a re-- lie'l valve on one member of the l.)elloWs,--- means for at'ztuating the same through the medium oi" the throttliw mechz'inism, and means 'l'or connecting the interior of the bellows with a workingtension. Wind chest, for the purpose described.

.l. in a. variable tr ision expression. bellows ol' the ehararter designated, the comliiination ol a port block mounted adjustably upon one member ol' the bellows, m vans for connecting said adjustable port block with a tension reservoir or exhaust mechanism, a valve blade connected with the other inen'iber oi the be lows, means l'or adjusting said port blocla with relation to the said valve blade, a relief valve in one member ol the bellows, means 'lor opening said reliel" valve during the col-- lapse of the bellows, a spring arranged to tend constantly to separate the members of the bellows, and means for connecting the interior ol' the bellows with the working tension ol' a wind chest for the purpose described.

1o: in a variable tension expression bellows of the rharaeler designated, the eon'tbination of a. port block mounted adjustab v upon the stationary member of the bellows, means for connecting said port block with a tension reservoir or exhaust mechanism, a valve blade pivotally connected with the movable member of the bellows and pivotally connected to the said adjustable port block, means for adjusting said. port block with relation to said valve blade, a relief valve mounted upon said movable member, means for opening the said relief valve during the collapse of the movable men'rber, and means for connecting the interior of the bellows with a working tension Wind chest, for the purpose described.

11. In a variable tension expression bellows of the character designated, the combination of a port block mounted adjustably upon the stationary member oil the bellows, means for connecting said port block with a tension reservoir or exhaust mechanism, a valve blade pivotally connected to the said adjustable port block andv with the i'novable member of the bellows, means for adj Listing said port block with relation to said valve blade, a relief valve mounted upon said. 1uovable member, means upon. the said port block for opening the said relie'l" vai. and. means for connecting the interior of the bellows with a working tension wind chest, for the purpose described.

12. in a variable tension expression bellows ol the character designated, the combination oil a port block mounted adjustably upon the movable member of a pneumatic in said bellows, said pl'ieumati 't:ommuni(:at

ing with a. tension reservoir or exhaust mechanism, a valve blade coor'teclml with one member of the bellows, means *l'or adjusting said port block with relation to said valve blade and means for connecting the interior of the bellows with a working wind tension chest, for the purpose deseriiwd.

GEORGE BRAND.

ifitnesses:

.1). VJ. GARDNER, Gnu. WM. Mmir'r. 

